Top-down versus bottom-up forecasting strategies

Some controversy exists about the advocacy of top-down versus bottom-up forecasting strategies. Top-down forecasting refers to the process of forecasting the demand for the aggregate of items in a class and then inferring individual demands according to a percentage of the total; bottom-up refers to separately forecasting the requirements for each individual item. This paper outlines the relative advantages of each strategy and indicates the situations in which each should be preferred.     

Surveying a subsea lava flow using the Autonomous Benthic Explorer (ABE)

This paper summarizes results from the first science deployment of the Autonomous Benthic Explorer (ABE), conducted on the Juan de Fuca Ridge (46°N, 129°W) at depths between 2200 and 2400 m. Using long baseline acoustic transponders, the ABE descended with precision to a preassigned starting point, then executed dead-reckoned tracklines. It followed the bottom at distances between 7 and 20 m using an acoustic fathometer as a reference sensor. The ABE mapped a new subsea lava flow with a magnetometer, imaged the seafloor with a stereo snapshot video system, and mapped a hydro thermal plume with conductivity and temperature sensors. The ABE completed 7 successful dives and covered over 35 km of tracklines. Detailed power records were logged, which permits extrapolation of the ABE's performance to other missions and higher capacity batteries.     

ON EMPIRICAL DISCONFIRMATIONS OF EQUIVOCAL DEDUCTIONS WITH INSUFFICIENT DATA.

D. L. VARBLE'S (SEE 42:9) CONCLUSIONS REGARDING THE ROLE OF SOCIAL REINFORCEMENT IN THE MODIFICATION OF VERBAL BEHAVIOR ARE QUESTIONED ON BOTH PROCEDURAL AND CONCEPTUAL GROUNDS. IN INTERVIEW SITUATIONS THERAPISTS SIMULTANEOUSLY REINFORCE NUMEROUS CLASSES OF RESPONSES ON DIFFERENT SCHEDULES; CONSEQUENTLY, AN ADEQUATE TEST OF REINFORCEMENT EFFECTS MUST INCLUDE ASSESSMENT OF ALL MAJOR RESPONSE CHANGES ALONG WITH THEIR ASSOCIATED PATTERNS OF REINFORCEMENT. MOREOVER, THE EFFECTS OF SELECTIVE REINFORCEMENT CANNOT BE REVEALED WHEN APPROVED AND DISAPPROVED CLASSES OF RESPONSE ARE COMBINED INTO A SINGLE DEPENDENT MEASURE. THE NEED FOR CLOSE LINKAGES BETWEEN BEHAVIORAL OUTCOMES AND THEIR CONTROLLING VARIABLES IN PSYCHOTHERAPY RESEARCH IS STRESSED. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

VISUAL ACUITY AS MEASURED BY DYNAMIC AND STATIC TESTS: A COMPARATIVE EVALUATION.

IN ORDER TO PROVIDE, FOR THE 1ST TIME, DEFINITIVE INFORMATION ON THE RELATIONSHIP BETWEEN STATIC VISUAL ACUITY AND ACUITY FOR A MOVING TARGET (DYNAMIC VISUAL ACUITY), BOTH TYPES OF ACUITY WERE MEASURED FOR 17,500 SS, AGES 16-92. THE RESULTS SHOW: (1) ACUITY DECLINES PROGRESSIVELY WITH BOTH INCREASING SPEED OF TARGET MOVEMENT AND ADVANCING AGE, (2) MALES HAVE CONSISTENTLY BETTER ACUITY (BOTH STATIC AND DYNAMIC) THAN FEMALES, AND (3) HIGH INTERCORRELATIONS EXIST BETWEEN THE STATIC AND DYNAMIC TESTS, THESE CORRELATIONS DECREASING WITH INCREASING SPEED OF TARGET MOVEMENT. THESE FINDINGS ARE PRESENTED PRIMARILY FOR THEIR VALUE IN PROVIDING NORMATIVE DATA TO OTHER RESEARCHERS. ADDITIONAL RESEARCH IS SUGGESTED TO EXPLAIN SOME OF THE RELATIONSHIPS OBTAINED. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of Solid-State Microwave Annealing with Conventional Furnace Annealing of Ion-Implanted SiC

Rapid solid-state microwave annealing was performed for the first time on N⁺-, Al⁺-, and B⁺-implanted SiC, and the results were compared with the conventional furnace annealing. For microwave annealing, temperatures up to 2,000 °C were attained with heating rates exceeding 600 °C/s. An 1,850 °C/35 s microwave anneal yielded a root-mean-square (RMS) surface roughness of 2 nm, which is lower than the 6 nm obtained for 1,500 °C/15 min conventional furnace annealing. For the Al implants, a minimum room-temperature sheet resistance (R _s ) of 7 kΩ/□ was measured upon microwave annealing. For the microwave annealing, Rutherford backscattering (RBS) measurements indicated a better structural quality, and secondary-ion-mass-spectrometry (SIMS) boron implant depth profiles showed reduced boron redistribution compared to the corresponding results of the furnace annealing.     

ON THE PATH PLANNING PROBLEM IN THE VICINITY OF OBSTACLES

This paper presents a new approach to motion planning in the neighborhood of obstacles. The technique presented here, the configuration space vector path planner CSVPP , generates a collision-free path for a robot amongst unknown arbitrarily shaped obstacles. The CSVPP algorithm utilizes discrete vectors in the configuration space of the robot to generate a path between any two points in the robot's dynamic time-varying workspace. The calculation of the robot's path assumes interpolated joint control, and provides a computational speed that enables the algorithm to be implemented in real time. A number of simulations are provided for several varying environments.